System and method for recycling non-reusable refrigerant containers

ABSTRACT

A system and method for recycling non-reusable refrigerant transport containers. At least one intact refrigerant transport container is received into a sealed chamber. The refrigerant transport container is punctured to release residual refrigerant, which is removed and compressed. The container is shredded and/or compacted. A refrigerant transport container deposit program is provided, comprising: encoding a deposit container prior to use; receiving the encoded spent container and releasing the imposed deposit; automatically removing residual refrigerant from the spent container; and recycling materials from the refrigerant transport container. A database storing a record relating to the encoded refrigerant transport containers may be employed for tracking.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of U.S. patent applicationSer. No. 14/252,899, filed Apr. 15, 2014, now U.S. Pat. No. 9,198,891,issued Dec. 13, 2016, which is a Continuation of U.S. patent applicationSer. No. 14/038,838, filed Sep. 27, 2013, now U.S. Pat. No. 8,695,364,issued Apr. 15, 2014, which is a Continuation of U.S. patent applicationSer. No. 13/532,929, filed Jun. 26, 2012, now U.S. Pat. No. 8,544,287,issued Oct. 1, 2013, which is a Continuation of U.S. patent applicationSer. No. 12/251,385, filed Oct. 14, 2008, now U.S. Pat. No. 8,205,462,issued Jun. 26, 2012, which claims benefit of priority from U.S.Provisional Patent Application Ser. No. 60/979,840, filed Oct. 14, 2007,the entirety of which is expressly incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to material recycling devices, and methodsof use therefore.

BACKGROUND OF THE INVENTION

In 2006, the U.S. Environmental Protection Agency commissioned theUniversal Technical Institute in Avondale, Ariz. to conduct tests todetermine the amount of refrigerant remaining in do-it-yourself (DIY)small cans and professional 30 pound cylinders used to charge motorvehicle air conditioning (MVAC) systems. See, “Disposable Container HeelTesting Study Report”, Prepared for: United States EnvironmentalProtection Agency Stratospheric Protection Division, Task Order No. 11,Contract No. EP-W-06-010 (Mar. 21, 2007), and peer review report, eachof which is expressly incorporated herein by reference.

Under typical situations, any refrigerant remaining in disposablecontainers after charging a MVAC system is ultimately eventuallyreleased to the atmosphere. The releases are referred to as “heelemissions.” For small cans, the tests analyzed the heel remaining aftervarious charging times under different scenarios. The tests of 30 poundcylinders quantified the heel remaining in cylinders that had beenremoved from service as “empty.”

Current MVAC systems use HFC-134a (1,1,1,2-Tetrafluoroethane)refrigerant. MVAC refrigerant emissions can come from leaks in thesystem, from servicing, and from end-of-life disposal. Servicingemissions can occur either at professional repair shops or throughdo-it-yourself (DIY) servicing. Repair shops generally use 30 poundcylinders and refrigerant recovery/recycling machines that minimizeemissions. Do-it-yourselfers (DIYers) use small cans (typically 12ounces) of refrigerant to recharge or top off an MVAC without the aid ofcertified service equipment.

Tests of 30 pound cylinder heels measured the amount of refrigerantremaining in the cylinder after a service shop had determined it wasempty and had removed it from the charging equipment. The techniciansconducted the tests at standard room temperatures. They weighed eachcylinder before recovery of the cylinder contents, and measured andrecorded the initial cylinder pressure. With the recovery/recyclingmachine, they performed two recovery cycles on each cylinder andmeasured the cylinder weights after each recovery cycle. The technicianspulled a vacuum (10 to 15 in. Hg) during the first recovery cycle. Therecovery was completed after the pressure stabilized. They used adifferent procedure during the second recovery cycle to examine theeffects of pulling a deeper vacuum (30 in. Hg). They also applied a heatblanket during the second recovery and oriented the cylinders upsidedown to transfer the refrigerant in the liquid phase.

The heel testing results for each of six 30 pound cylinders show thatthe average heel was 1.85%, with a range from 0.302 to 4.46%. This meansthat an average of 0.55 pounds, and a range of 0.09-1.39 pounds remainin the cylinder after exhaustion in the field.

Similar 30 pound cylinders are used in other industries, and variousrefrigerant gasses are transported in similar containers. However, theissue of residual gas remaining in the cylinder after use remainsapparent in all such cases.

The cylinders are generally single use because reuse would requiredetermination of contaminant status and DOT container certificationstatus, possible inspection and retesting, and significant logisticaloverhead in returning the containers to refilling plants. On the otherhand, non-reusable containers are “virgin”, and are efficientlymanufactured from steel, tested, filled and distributed. Of course, theexhausted containers end up in landfills, eventually leaking theirresidual content.

SUMMARY OF THE INVENTION

The present invention provide systems and methods for efficientlyrecycling single use refrigerant transport containers, while avoidingenvironmental release of their residual content. Two basic embodimentsare provided: a first embodiment wherein containers and their contentsare recycled and/or reclaimed in bulk, and a second embodiment whichrecycles one container at a time.

The present invention also provides a system and method foradministering a deposit/refund program for incentivizing recycling ofthe non-reusable refrigerant transport and distribution containers forservice use.

The first embodiment of the invention provides a sealed dual chambersystem, with a shredder and two separate vacuum systems.

In operation, one or more spent refrigerant containers are fed into anupper chamber, above a shredder unit, and the access door closed andsealed. A vacuum pump is then operated to fully evacuate the air fromwithin the chamber and it's communicating spaces. For example, a vacuumis drawn to 30 inches of mercury, leaving very little residualnon-condensing gasses. The shredder unit is then operated, with therefrigerant containers gravity fed downward. The first action of theshredder is to puncture the refrigerant container, and thus permitaccess to the residual content within the container. The shredder thencontinues to shred the steel container, with the shredded steel droppingto a lower chamber. This process can continue continuously until allcontainers are punctured and then shredded. While the size of this unitis arbitrary, the upper chamber may, for example, hold ten refrigerantcontainers. It is useful to have the upper chamber as full as possible,since remaining dead space would have to be evacuated in the initialpump down phase.

After the pump down and removal of non-condensing gasses, andconcurrently or subsequent with the shredding, a second compressor isoperated to withdraw and recycle the refrigerant released into thechamber. The compressor may be operated for example to draw down to 29inches of mercury.

Since there is no air in the chamber, even if the refrigerant is aflammable type, there is little or no risk of explosion. Likewise, thechamber itself may be designed to be explosion-proof.

When the containers are all shredded, and the refrigerant fullywithdrawn from the space, the upper and/or lower chamber may be opened,to insert additional containers and remove the shredded steel in thebase.

It is often useful to ensure that the refrigerant gasses collectedduring a pooling operation, such as would occur with multiple containerrecycling, are of a single type, since mixed gas requires significantprocessing. Therefore, it is preferred that the containers entering therecycling system during a single operation all are of the same type.Fortunately, the industry has adopted a color code for the containers,so that it is readily possible to stipulate a manual process whichensures that the containers inserted all are of the same type. Anautomated system having an automated control 1 may also be implementedto inspect the color of the containers entering the system. While notpresently implemented as an industry standard, a bar code may be placedon the various containers, which will permit identification and trackingof encoded refrigerant transport containers 7, which will be discussedin more detail below. The bar code may be automatically read by anautomated bar code reader 2, or manually scanned, as the containers areinserted into the device.

When recycling refrigerants, they should be maintained separately. Forexample, each complete cycle of the system may transfer the contents ofthe recycled containers to a single receiving vessel, which can then beanalyzed and recovered later, for example at a central facility. On theother hand, the system may also employ a real time analyzer 3, forexample having an infrared optical sensor 4, to determine the type ofgas and purity as it is being withdrawn from the system. If the gas isdetermined to be pure, and of a single type, it may be routed to acollection vessel predesignated or designated at that time for thattype. If it is impure, it may be routed to a separate vessel or vessels.

The collection vessels may be, for example, reusable or disposablecontainers, which may then be themselves recycled.

The second embodiment of the invention is similar in concept to thefirst; however it is intended for individual recycling of containers,one at a time. This embodiment may also be useful for recycling small,e.g., 12 oz. containers. Small retail containers tend to have UPC barcodes, which may assist in identification and optimal recycling.

In this case, an individual container is inserted into a chamber, whichwill generally be cylindrical or conform to the envelope of thecontainer. A hatch is closed and sealed, and the vacuum pump exhaustsgas from the chamber, to, e.g., a 30 inch Hg vacuum. The cylinder isthen punctured, for example with a lance, to allow release of thecontents to the exterior space. The compressor is then operated toremove residual refrigerant, for example down to a 29 inch Hg vacuum.The steel container may then be shredded, either under vacuum,potentially concurrently with the operation of the compressor, or in aseparate operation. Indeed, the container may be separately shreddedafter removal of refrigerant, in a separate operation. Advantageously,the system does not require a manual transfer step, and therefore it isshredded in place. However, in this embodiment, it is not necessary thatthe shredder components be present in the vacuum space; that is, thevacuum pump and compressor operations may be conducted on the containerin the intact, and punctured states respectively, and then the shreddercomponents may be exposed to complete the process. Since this embodimentwill generally be compact, for example refrigerator sized (6-8 ft tall,3-5 feet wide, 3-5 feet deep), and the vacuum and compressor operationswill require some time to complete, the shredder may be a relativelyslow processor. For example, a sliding door may be placed below thecontainer, such that after completion of refrigerant removal, thecontainer is permitted to drop to a low chamber, where the shreddingtakes place while the upper chamber is made available for a subsequentrefrigerant removal operation.

The vacuum pump and compressor are of known type to persons of ordinaryskill in the art. The shredder may be, for example, of a moving bladetype used in steel sheet recycling operations, though adapted to fitwithin the confines of the system as described. In place of theshredder, a crusher may also be employed, as may be appropriate.

Various components and methods may also be adopted from U.S. Pat. No.6,141,977, expressly incorporated herein by reference.

In order to incentivize return of containers, a deposit system isproposed. Because the point of supply may be different than the point ofreturn, the proposed system employs electronic tracking. While any sortof tracking may be suitable, such as bar codes, RF-ID, documents, etc.,bar codes are preferred because they can be automatically read, maycontain sufficient individual unit identifying information and securityfeatures to deter tampering, and are part of a relatively low costinfrastructure.

Thus, upon distribution of the container, a bar code 5 placed on thecylinder during manufacture or filling is read by an automated bar codereader 2, a deposit fee charged, and an information record transmittedby an automated control 1 to a database 6. In some cases, a purchasermay be identified in the record, but this may not be necessary.Advantageously, the content of the encoded refrigerant transportcontainer 7 is coded, as well as a unique identifier provided.

Upon return to a recycling center, which may be the same or differentfrom the point of sale or distribution, the bar code 5 is read by anautomated bar code reader 2 at such time when the recycling of thecontainer is committed. For example, as it is being inserted into therecycling chamber itself. The bar code 5 is then analyzed to determinethe type of refrigerant, which may impact the refrigerant capture phaseof operations. In a bulk recycling system, e.g., the first embodiment,the automated bar code reader 2 may be used to ensure that refrigeranttypes are not mixed, and/or that prohibited types are not included. Oncethe encoded refrigerant transport container 7 is accepted for recycling,the original database record may be updated, and the deposit released.In one case, the tracking of deposits is automated, and so long as theencoded refrigerant transport container 7 is recycled, the owner of thedeposit is credited. On another case, the presenter of the encodedrefrigerant transport container 7 is credited, with perhaps a flag inthe database record to indicate potential theft or fraud.

The refrigerant withdrawn from the containers, as well as the scrapsteel and brass fittings, may have some value, and therefore there ispotential for subsidy of the recycling operations from that revenuesource. However, more typically, the recycling operation is funded by,for example, unredeemed deposits, and payments made by distributors orusers. For example, a recycling fee may be charged or implied at thetime of purchase or distribution of the container.

Therefore, the present invention provides various embodiments of systemsand methods for recycling materials from non-reusable refrigeranttransport vessels, and alleviate what has been deemed a potentiallysignificant problem.

It is therefore an object of the invention to provide a system andmethod for recycling no-reusable refrigerant transport containers,comprising receiving at least one intact refrigerant transport containerinto a chamber, evacuating non-condensing gasses from the chamber,puncturing the intact refrigerant transport container to releaseresidual refrigerant therein, removing and compressing the residualrefrigerant, and shredding and/or compacting the refrigerant transportcontainer.

It is a further object of the invention to provide a system and methodfor implementing a refrigerant transport container deposit program,comprising encoding a refrigerant transport container prior to use andimposing a deposit thereon, receiving a spent refrigerant transportcontainer at a recycling facility, releasing the deposit, automaticallyremoving residual refrigerant from the refrigerant transport container,and recycling the refrigerant transport container materials.

These and other objects will become apparent. For a full understandingof the present invention, reference should now be made to the followingdetailed description of the preferred embodiments of the invention asillustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the accompanyingdrawings, in which:

FIG. 1 shows a mechanical structure of a system according to the firstembodiment of the invention; and

FIG. 2 shows a schematic diagram of a system according to the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1, an upper door 10 is provided for insertion of thecontainers for recycling. After one or more containers 11 are inserted,the door 10 is clamped shut. As discussed above, but not shown in FIG.1, the containers 11 may be coded, such as the encoded refrigeranttransport container 7 shown in FIG. 2, for example color coded or barcoded with bar code 5, and an automated bar code reader 2 provided todetermine the encoded refrigerant transport container 7 type. A blockmay be provided to prevent insertion of containers of a wrong orinappropriate type. The coding may be used to determine a destination ofthe refrigerant once reclaimed. The coding may also be used inconjunction with a container deposit program.

The chambers 12, 13, once sealed, are then evacuated with a vacuum pump14. Since the refrigerant containers are still intact, this evacuationmay be to atmosphere, and is intended to eliminate non-condensing gasesfrom the chamber(s) 12, 13.

After the chambers 12, 13 are evacuated, for example to a 30 inch Hgvacuum, by the vacuum pump 14, the shredder 15 below the top chamber isthen operated, which initially punctures a container 10 to releaserefrigerant, and then proceeds to shred the steel container it itsentirety, allowing the shreds to drop into the lower chamber 13. Ingeneral, the shredder 15 will operate on one container 11 at a time,sequentially shredding the various containers in the chamber 12 untilcomplete.

After the chambers 12, 13 are evacuated of non-condensing gasses, andbefore the chambers 12, 13 again opened to the atmosphere, a compressor16 is operated to remove refrigerant from the sealed chambers 12, 13.This compressor 16 is operated to remove traces of refrigerant, forexample to a vacuum of 29 inches of Hg.

During operation, an analyzer 17, e.g., an infrared analyzer, isoperated to detect the type, and optionally purity of gas in thechambers 12, 13. If the gas is of a known type, and pure, it can bepooled with prior recovered refrigerant of the same type. Otherwise, itmay be collected in a separate container 18 for later reclamation orproper disposal.

After the last container 11 in the chamber is shredded, and the residualrefrigerant recovered, the upper chamber 12 may be reopened, andadditional containers 11 inserted for processing. The lower chamber 13may also be opened to remove shredded sheet and fittings, though thisneed not be done as often.

There has thus been shown and described novel refrigerant recovery andtransport container recycling systems and methods which fulfill all theobjects and advantages sought therefor. Many changes, modifications,variations, combinations, subcombinations and other uses andapplications of the subject invention will, however, become apparent tothose skilled in the art after considering this specification and theaccompanying drawings which disclose the preferred embodiments thereof.All such changes, modifications, variations and other uses andapplications which do not depart from the spirit and scope of theinvention are deemed to be covered by the invention, which is to belimited only by the claims which follow.

What is claimed is:
 1. A method for recycling refrigerant, comprising:identifying a container configured to hold a recovered refrigerant withat least one of optically or radio frequency-encoded unit identifyinginformation; automatically analyzing a type and determining a quantityof the recovered refrigerant within the container; and storing at leastone record representing the type and the quantity of the recoveredrefrigerant within the container in association with the unitidentifying information of the container in a database accounting forthe container and the recovered refrigerant within the container.
 2. Themethod according to claim 1, wherein the container comprises anon-reusable refrigerant transport container.
 3. The method according toclaim 1, wherein said identifying comprises optically reading the unitidentifying information from an optically-readable code on thecontainer.
 4. The method according to claim 1, further comprisingautomatically removing the recovered refrigerant from the containerafter said automatically analyzing.
 5. The method according to claim 4,further comprising compressing and storing the recovered refrigerantremoved from the container in at least one of a plurality of availablestorage vessels selectively in dependence of said automaticallyanalyzing.
 6. The method according to claim 5, further comprisingstoring the compressed recovered refrigerant in the at least one of aplurality of available storage vessels selectively in dependence on atype of the recovered refrigerant.
 7. The method according to claim 1,wherein the container is a reusable container, further comprisingaccounting for at least a deposit on the reusable container.
 8. Themethod according to claim 1, further comprising determining a purity ofthe recovered refrigerant.
 9. The method according to claim 8, furthercomprising accounting for a type, purity and quantity of the recoveredrefrigerant.
 10. A system for recycling refrigerant, comprising: anautomated reader comprising at least one of an optical or radiofrequency receiver configured to read at least one of optically or radiofrequency-encoded unit identifying information of a container configuredto hold a recovered refrigerant; an analysis system, configured toanalyze a type of the recovered refrigerant within the container, and todetermine a quantity of the recovered refrigerant within the container;and a database interface, configured to communicate information definingat least one database record representing the type and the quantity ofthe recovered refrigerant within the container in association with theunit identifying information of the container.
 11. The system accordingto claim 10, wherein the automated reader is configured to read the unitidentifying information as an optically-readable code on the container.12. The system according to claim 10, further comprising a vacuum systemconfigured to automatically remove the recovered refrigerant from thecontainer.
 13. The system according to claim 12, further comprising acompressor configured to compress the recovered refrigerant removed fromthe container.
 14. The system according to claim 13, further comprisinga plurality of storage vessels, wherein the compressed recoveredrefrigerant removed from the container is selectively stored in one ofthe plurality of storage vessels in dependence on an output of theanalysis system.
 15. The system according to claim 10, wherein thecontainer is a reusable container, and wherein the database interface isfurther configured to communicate information for accounting for atleast a deposit on the reusable container.
 16. The system according toclaim 10, wherein the analysis system is further configured to determinea purity of the recovered refrigerant.
 17. A system for recycling arefrigerant container having refrigerant content, comprising: at leastone of an electronic optical or radio frequency reader configured toidentify the refrigerant container and a type of a refrigerant in therefrigerant container, by reading a machine-readable code provided onthe refrigerant container; an analyzer, configured to determine at leasta purity and an amount of the refrigerant in the refrigerant container;and at least one pump, configured to remove a volatile content of therefrigerant container to at least sample a contents of the refrigerantcontainer for the analyzer in a first phase, and to withdraw all of therefrigerant in the refrigerant container in a second phase.
 18. Thesystem according to claim 17, further comprising: a plurality of liquidrefrigerant storage vessels, each configured to separately store liquidrefrigerant received from the at least one pump, wherein the liquid isselectively stored in at least one of a plurality of liquid refrigerantstorage vessels selectively dependent on at least the type of therefrigerant in the refrigerant container.
 19. The system according toclaim 17, further comprising a database interface configured tocommunicate information defining accounting records comprising theidentity of the refrigerant container and the purity and the amount ofthe refrigerant in the refrigerant container.
 20. The system accordingto claim 17, wherein the machine readable code comprises a bar code onthe refrigerant container.